Car Accelerates On Its Own problems of the 2008 Lexus IS

I bought 2008 Lexus Is250 with 123k miles on 05/18/19. I had inspected by a mechanic prior to purchasing it. On one ocassion pror to accident, I backed out of a drive way. When I shifted the automatic transmission from reverse to drive it sudden accelerated for a brief moment, but it was clear in front of me and I remain in control. It only happened to me that one time that week and I thought nothing of it. In the morning of may 29, 2019 the car was parallel parked with a vehicle both in front behind it. My wife slowly back up the car to allow room to pull out of the parking spot. She turn the front wheels towards the curb so that the front of the car would slightly stick out. When she shifted the automatic transmission from reverse to drive, the car suddenly accelerated, jump over the curb and hit the concrete wall of a school. She panicked at the sudden acceleration and does not remember if she step on any pedal during that time. She only knows it accelerated as soon as she shifted to drive and then the car hit the wall. There were no injuries and no other car was involved. We moved the car off the side walk and notified the insurance and the school admin. The insurance declared it a total loss and took ownership of it. A gasoline car accelerate by opening the throttle to allow more air into the engine. The electronic throttle suddenly open due to the physical electronics and/or software controlling it when the transmission Is shift between reverse and drive. Dr. Ronald a. Belt theory seems plausible. If true you would think just changing the software to get an average of voltage samples would prevent the over compensation of the ecu throttle controller cause by low voltage spikes. . Read more...

In early 02/09 I was driving home on interstate 695 n in maryland. I was traveling about 50 mph, when all of a sudden the car suddenly accelerated to about 95 mph through no effort of my own. I did not engage the accelerator pedal to increase the speed of the vehicle. I immediately engaged the foot brake to decelerate and but the car would not slow. Eventually after several attempts I was able to slow the car with the brake but the engine continued to violently rev. As I released the foot brake, the car once again accelerated without engaging the accelerator pedal. Even after engaging the emergency brake, the unaided acceleration and my attempt to decelerate the car continued. I was finally able to slow the car enough to pull out of traffic and over to the emergency lane and eventually stop the motion of the vehicle. Although I was able to bring the car to a stop, the engine continued to rev violently, the back tires spun out of control and the back of the car started to fish tail. I tried a number of different tactics to stop the car completely including, attempting to manually shift gears, putting the car in neutral etc. Finally, after several minutes I was able to turn off the ignition and bring the car to a complete stop and the ordeal came to an end without damaging the car and more importantly without injury to me or others. I had the car towed to dealership that night and explained the situation to the service organization the following day. The service team conducted multiple diagnostic tests but was unable to determine or explain the cause of the unintended acceleration to my satisfaction. One service rep suggested that the floor mat was the cause but I had checked immediately after the ordeal the night before to ensure that the floor mat had not become lodged under the accelerator pedal. Since the dealership was not able to determine the cause of the problem, I decided that the best course of action was to return the car and lease another car.